How to Build Your Own AI Chatbot Like ChatGPT (From Scratch)

6/28/20251 min read

Ever dreamed of building your own AI chatbot like ChatGPT? Whether you’re a solo dev, startup founder, or hobbyist, this tutorial will guide you step-by-step through building a smart, responsive chatbot using OpenAI’s GPT models, Python, and Flask.

What You’ll Build

You’ll create a fully functional chatbot app that:

Accepts user input
Sends it to OpenAI’s GPT-3.5/4 model
Displays the AI-generated response
Can be extended with memory, APIs, or custom UIs

Prerequisites

Python 3.9+
OpenAI API key from platform.openai.com
Basic HTML/CSS knowledge (for frontend)

Install dependencies:

Step 1: Set Up Your Project

Create a new folder called chatbot_app and inside it, add:

app.py (main backend)
templates/index.html (frontend)

Step 2: The Python Backend (Flask + OpenAI)

app.py

Step 3: The HTML Frontend

templates/index.html

Step 4: Run Your Chatbot

Start the Flask server:

Open http://127.0.0.1:5000 in your browser, and start chatting!

Why Build Your Own Chatbot?

You control the prompt, interface, and data
Customize it for your product or audience
It’s a great startup or portfolio project

Final Thoughts

In just a few lines of Python and HTML, you’ve created your own ChatGPT-style AI chatbot. With this foundation, you can now add memory, knowledge bases, or integrate APIs to build next-gen AI products.

Want to Level Up Your Chatbot?

Add Memory to Your Chatbot [Read Article]
Style It with Tailwind CSS or Bootstrap [Read Article]
Deploy using Render, Railway, or Vercel [Read Article]
Add Voice Input & Output [Read Article]